From: Douglas Anderson Date: Fri, 3 May 2024 21:32:48 +0000 (-0700) Subject: drm/panel: edp: Add a comment about unprepare+disable at shutdown/remove X-Git-Tag: v6.11-rc1~141^2~24^2~24 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=ec7629859331fb67dbfb6bcd47f887a402e390ff;p=thirdparty%2Flinux.git drm/panel: edp: Add a comment about unprepare+disable at shutdown/remove It's the responsibility of a correctly written DRM modeset driver to call drm_atomic_helper_shutdown() at shutdown time and that should be disabling / unpreparing the panel if needed. Panel drivers shouldn't be calling these functions themselves. A recent effort was made to fix as many DRM modeset drivers as possible [1] [2] [3] and most drivers are fixed now. Unfortunately, it's very difficult to know exactly which DRM modeset drivers are using panel-edp due to the sheer number of panels it handles. For now, we'll leave the calls and just add a comment to keep people from copying this code. [1] https://lore.kernel.org/r/20230901234015.566018-1-dianders@chromium.org [2] https://lore.kernel.org/r/20230901234202.566951-1-dianders@chromium.org [3] https://lore.kernel.org/r/20230921192749.1542462-1-dianders@chromium.org Acked-by: Linus Walleij Acked-by: Maxime Ripard Signed-off-by: Douglas Anderson Link: https://patchwork.freedesktop.org/patch/msgid/20240503143327.RFT.v2.7.Icff7f7005d997773d585e36aba9ed41a9865201f@changeid --- diff --git a/drivers/gpu/drm/panel/panel-edp.c b/drivers/gpu/drm/panel/panel-edp.c index 970cfe504252f..eb7530ff00755 100644 --- a/drivers/gpu/drm/panel/panel-edp.c +++ b/drivers/gpu/drm/panel/panel-edp.c @@ -944,13 +944,34 @@ err_finished_ddc_init: return err; } -static void panel_edp_remove(struct device *dev) +static void panel_edp_shutdown(struct device *dev) { struct panel_edp *panel = dev_get_drvdata(dev); - drm_panel_remove(&panel->base); + /* + * NOTE: the following two calls don't really belong here. It is the + * responsibility of a correctly written DRM modeset driver to call + * drm_atomic_helper_shutdown() at shutdown time and that should + * cause the panel to be disabled / unprepared if needed. For now, + * however, we'll keep these calls due to the sheer number of + * different DRM modeset drivers used with panel-edp. The fact that + * we're calling these and _also_ the drm_atomic_helper_shutdown() + * will try to disable/unprepare means that we can get a warning about + * trying to disable/unprepare an already disabled/unprepared panel, + * but that's something we'll have to live with until we've confirmed + * that all DRM modeset drivers are properly calling + * drm_atomic_helper_shutdown(). + */ drm_panel_disable(&panel->base); drm_panel_unprepare(&panel->base); +} + +static void panel_edp_remove(struct device *dev) +{ + struct panel_edp *panel = dev_get_drvdata(dev); + + drm_panel_remove(&panel->base); + panel_edp_shutdown(dev); pm_runtime_dont_use_autosuspend(dev); pm_runtime_disable(dev); @@ -961,14 +982,6 @@ static void panel_edp_remove(struct device *dev) panel->drm_edid = NULL; } -static void panel_edp_shutdown(struct device *dev) -{ - struct panel_edp *panel = dev_get_drvdata(dev); - - drm_panel_disable(&panel->base); - drm_panel_unprepare(&panel->base); -} - static const struct display_timing auo_b101ean01_timing = { .pixelclock = { 65300000, 72500000, 75000000 }, .hactive = { 1280, 1280, 1280 },